Deck 49: Gas Exchange: the Respiratory System

Question 1

Which sequence presents the insect tracheal system structures in the correct order, from most external to most internal?

A)tracheoles, tracheae, tracheal branches, spiracles
B)tracheoles, tracheal branches, tracheae, spiracles
C)spiracles, tracheae, tracheal branches, tracheoles
D)spiracles, tracheoles, tracheae, tracheal branches

Answer 1

C

Question 2

Which respiratory surface property enhances the diffusion of respiratory gases?

A)cool temperatures
B)a thick epithelial layer
C)a large surface area
D)the presence of active transport pumps

Answer 2

C

Question 3

Which airway structure acts as the "windpipe"?

A)the bronchus
B)the bronchiole
C)the larynx
D)the trachea

Answer 3

D

Question 4

Which of the following respiratory surfaces lack physical protection from the external environment?

A)internal gills
B)lungs
C)tracheal system tubes
D)external gills

Question 5

Which animals use positive pressure breathing to ventilate their lungs?

A)reptiles
B)birds
C)dogs
D)frogs

Question 6

Why does countercurrent exchange optimize gas exchange across some gills?

A)It sustains an optimal thermal environment for gas exchange.
B)It optimizes perfusion to the respiratory surface.
C)It sustains an optimal respiratory gas concentration gradient.
D)It optimizes delivery of the respiratory medium to the respiratory surface.

Question 7

What is a disadvantage of air as a respiratory medium?

A)Air is 1000 times less dense than water.
B)Air requires less energy to ventilate over the respiratory surface.
C)Air evaporates water from the respiratory surface.
D)Air contains 30 times as much O₂ as water.

Question 8

Which of the following is involved in both cellular respiration and physiological respiration in humans?

A)the respiratory surface
B)the circulatory system
C)mitochondria
D)the respiratory medium

Question 9

Which of the following animals have the highest O₂ consumption per gram ever recorded for animals?

A)aquatic animals
B)insects at rest
C)insects at flight
D)birds at flight

Question 10

Which of the following is an example of local control over breathing?

A)the interneuron groups of the pons refining the contractions involved with inhalation and exhalation
B)the aortic bodies signalling an increase in breathing rate when blood pH is acidic
C)the carotid bodies signalling an increase in breathing rate when O₂ levels are low
D)automated lung ventilation and lung perfusion adjustments maximizing O₂ and CO₂ exchange

Question 11

Which of the following air-filled respiratory system structures are common in insects?

A)tracheal tubes
B)lungs
C)gills
D)integumentary surfaces

Question 12

Why is it important that CO₂ be rapidly removed from the cells of animals?

A)because high cellular CO₂ affects cellular respiration
B)because high cellular CO₂ is a narcotic poison
C)because CO₂ damages nerve function
D)because CO₂ damages muscle function

Question 13

Which of the following is an example of a respiratory surface?

A)fish fins
B)human nose
C)reptilian skin
D)human lungs

Question 14

If N₂ gas comprises 79% of atmospheric air at sea level, what is the partial pressure of N₂?

A)about 300 mm Hg
B)about 500 mm Hg
C)about 600 mm Hg
D)about 700 mm Hg

Question 15

Where in an insect tracheal system does gas exchange occur between the air and a cell?

A)in the tracheoles
B)in the tracheal branches
C)in the trachea
D)in the gill filaments

Question 16

In which animal would perfusion be least efficient during gas exchange?

A)a fish
B)a bird
C)a flatworm
D)a human

Question 17

How much of O₂ from water flowing over gills is extracted by countercurrent exchange?

A)50 to 60%
B)60 to 70%
C)80 to 90%
D)90 to 100%

Question 18

Why is proper ventilation important for a respiring animal?

A)It directly increases gas exchange between the blood and cells.
B)It maintains blood circulation within the body of an animal.
C)It maintains proper O₂ and CO₂ levels on the internal side of the respiratory surface so that diffusion across it can be maintained.
D)It maintains proper O₂ and CO₂ levels on the external side of the respiratory surface so that diffusion across it can be maintained.

Question 19

Through what process is O₂ transported into the blood from air in the lungs?

A)active transport
B)osmosis
C)facilitated diffusion
D)simple diffusion

Question 20

Which of the following encourages the movement of water over gills?

A)beating cilia
B)a fish swimming with its mouth closed
C)the diaphragm contracting
D)a muscular tail contracting

Question 21

Which respiratory control centres are most sensitive to changes in CO₂?

A)the receptors of the cortex
B)the aortic bodies
C)the carotid bodies
D)the receptors of the medulla

Question 22

What is the name of the primary muscle involved in human breathing?

A)the diaphragm
B)the internal intercostals
C)the external intercostals
D)the abdominal wall muscles

Question 23

Which event occurs in lung blood?

A)Plasma HCO₃- enters erythrocytes.
B)In erythrocytes, carbonic anhydrase converts CO₂ and H₂O into HCO₃- and H⁺.
C)Free H⁺ binds to hemoglobin.
D)CO₂ binds to hemoglobin.

Question 24

Which lung volume keeps the lungs from completely deflating, even after a maximal exhalation?

A)vital capacity
B)total capacity
C)residual volume
D)tidal volume

Question 25

What would you predict to happen in an area of the body where blood is relatively cool?

A)CO₂ would bind more readily to hemoglobin.
B)O₂ would bind more readily to hemoglobin.
C)CO₂ would release from hemoglobin.
D)O₂ would release from hemoglobin.

Question 26

Which of the following is responsible for closing off the airway during swallowing?

A)the larynx
B)the epiglottis
C)the pharynx
D)the intercostal muscles

Question 27

Which organ's smooth muscles need to contract in order to reduce air movement to the mammalian respiratory surfaces?

A)those of the epiglottis
B)those of the large bronchi
C)those of the bronchioles
D)those of the trachea

Question 28

Which of the following occurs during human inhalation?

A)The diaphragm relaxes and the external intercostal muscles relax.
B)The diaphragm relaxes and the external intercostal muscles contract.
C)The diaphragm contracts and the external intercostal muscles relax.
D)The diaphragm contracts and the external intercostal muscles contract.

Question 29

What would you predict would happen in an area of the body where blood is relatively acidic (low pH)?

A)CO₂ would bind more readily to hemoglobin.
B)O₂ would release from hemoglobin.
C)CO₂ would release from hemoglobin.
D)O₂ would bind more readily to hemoglobin.

Question 30

Which term refers to the initial branches of the trachea that lead into each lung?

A)bronchioles
B)alveoli
C)pleura
D)bronchi

Question 31

How is most O₂ transported in the blood?

A)bound to hemoglobin
B)as gas
C)dissolved in the plasma
D)as bicarbonate ions

Question 32

A larynx is found at the beginning of each insect trachea.

Question 33

Which animal uses positive pressure breathing to ventilate its lungs?

A)a bird
B)a salamander
C)a lizard
D)a human

Question 34

Which event occurs in body tissue blood?

A)In the plasma, HCO₃- and H⁺ convert into CO₂ and H₂O.
B)Erythrocyte HCO₃- enters the plasma.
C)Free H⁺ releases from hemoglobin.
D)CO₂ binds to hemoglobin.

Question 35

What happens to the chest cavity and air pressure in the lungs during exhalation?

A)The chest cavity increases, and air pressure decreases.
B)The chest cavity increases, and air pressure also increases.
C)The chest cavity decreases, and air pressure increases.
D)The chest cavity decreases, and air pressure also decreases.

Question 36

Which animals use air sacs to ventilate their lungs?

A)reptiles
B)horses
C)birds
D)frogs

Question 37

Which term refers to the respiratory surfaces of mammalian lungs?

A)bronchioles
B)air sacs
C)bronchi
D)alveoli

Question 38

What is the function of carbonic anhydrase?

A)to speed up the rate at which CO₂ binds to hemoglobin
B)to speed up the rate at which CO₂ binds to O₂
C)to speed up the conversion of CO₂ and H₂O into HCO₃- and H⁺
D)to speed up the conversion of HCO₃- and O^- into CO₂ and H₂O

Question 39

Which chemical has the least influence on the regulation of breathing rate?

A)chemical O₂
B)chemical N₂
C)chemical H
D)chemical CO₂

Question 40

Among air-breathing animals, why do birds have the most effective mechanism of extracting oxygen from air?

A)because their air sacs provide additional respiratory surfaces
B)because birds utilize crosscurrent exchange
C)because bird lungs are the largest among vertebrates
D)because bird lungs have more surface area

Question 41

Alveoli are surrounded by pulmonary capillaries.

Question 42

Match each term with its description.
a.flow of blood (or body fluids) on the internal side of the respiratory surface
b.gas exchange between the blood and body tissue cells
c.general term used to describe an animal's exchange of gases with the respiratory medium
d.specifically describes the release of air from the lungs to the atmosphere
e.flow of the respiratory medium over the external side of the respiratory surface
f.occurs due to the expansion of the lungs and thoracic cavity
g.exchange of gases between the respiratory medium and the blood (or internal body fluids)
inhalation

Question 43

Birds utilize crosscurrent mechanisms to optimize diffusion of O₂ across their respiratory surfaces.

Question 44

Match each term with its description.
a.flow of blood (or body fluids) on the internal side of the respiratory surface
b.gas exchange between the blood and body tissue cells
c.general term used to describe an animal's exchange of gases with the respiratory medium
d.specifically describes the release of air from the lungs to the atmosphere
e.flow of the respiratory medium over the external side of the respiratory surface
f.occurs due to the expansion of the lungs and thoracic cavity
g.exchange of gases between the respiratory medium and the blood (or internal body fluids)
cellular respiration

Question 45

Match each term with its description.
a.flow of blood (or body fluids) on the internal side of the respiratory surface
b.gas exchange between the blood and body tissue cells
c.general term used to describe an animal's exchange of gases with the respiratory medium
d.specifically describes the release of air from the lungs to the atmosphere
e.flow of the respiratory medium over the external side of the respiratory surface
f.occurs due to the expansion of the lungs and thoracic cavity
g.exchange of gases between the respiratory medium and the blood (or internal body fluids)
breathing

Question 46

Humans ventilate their lungs by negative pressure breathing.

Question 47

Each molecule of hemoglobin can bind to six molecules of oxygen.

Question 48

CO₂ and H₂O are converted to HCO₃- and H⁺ in the blood of the lungs.

Question 49

Alveoli are the respiratory surfaces of birds.

Question 50

Blood O₂ levels have the greatest influence on mammalian breathing rate.

Question 51

Llamas, which are customarily known as mountain dwellers, have hemoglobin with a higher O₂ binding affinity than that of humans. That being said, how would you predict the llama hemoglobin-O₂ dissociation curve would differ from that of a human? (See diagram below.)

Question 52

Match each term with its description.
a.flow of blood (or body fluids) on the internal side of the respiratory surface
b.gas exchange between the blood and body tissue cells
c.general term used to describe an animal's exchange of gases with the respiratory medium
d.specifically describes the release of air from the lungs to the atmosphere
e.flow of the respiratory medium over the external side of the respiratory surface
f.occurs due to the expansion of the lungs and thoracic cavity
g.exchange of gases between the respiratory medium and the blood (or internal body fluids)
physiological respiration

Question 53

Match each term with its description.
a.flow of blood (or body fluids) on the internal side of the respiratory surface
b.gas exchange between the blood and body tissue cells
c.general term used to describe an animal's exchange of gases with the respiratory medium
d.specifically describes the release of air from the lungs to the atmosphere
e.flow of the respiratory medium over the external side of the respiratory surface
f.occurs due to the expansion of the lungs and thoracic cavity
g.exchange of gases between the respiratory medium and the blood (or internal body fluids)
exhalation

Question 54

Describe three adaptations that enhance the function of a respiratory surface.

Question 55

Match each term with its description.
a.flow of blood (or body fluids) on the internal side of the respiratory surface
b.gas exchange between the blood and body tissue cells
c.general term used to describe an animal's exchange of gases with the respiratory medium
d.specifically describes the release of air from the lungs to the atmosphere
e.flow of the respiratory medium over the external side of the respiratory surface
f.occurs due to the expansion of the lungs and thoracic cavity
g.exchange of gases between the respiratory medium and the blood (or internal body fluids)
ventilation

Question 56

Match each term with its description.
a.flow of blood (or body fluids) on the internal side of the respiratory surface
b.gas exchange between the blood and body tissue cells
c.general term used to describe an animal's exchange of gases with the respiratory medium
d.specifically describes the release of air from the lungs to the atmosphere
e.flow of the respiratory medium over the external side of the respiratory surface
f.occurs due to the expansion of the lungs and thoracic cavity
g.exchange of gases between the respiratory medium and the blood (or internal body fluids)
perfusion

Question 57

When the diaphragm contracts, it moves up into the thoracic cavity, thereby decreasing its volume.